<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*后代选择器*/
        /*.nav a{
            color: red;
        }*/
        /*子选择器*/
        .nav > a{
            color: red;
        }
    </style>
</head>
<body>
<div class="nav">
    <a href="#">一级超链接</a>
    <a href="#">一级超链接</a>
    <p><a href="#">二级超链接</a></p>
</div>
</body>
</html>